Filter Controls, Bass BOost Controls, Pre-OUTS

Filter Controls

The active filter built into each channel section of the J2-320.4 can be used to eliminate potentially harmful and/or undesired frequencies from making their way through the amplifier sections to the speaker(s). This serves to improve tonal balance and to avoid distortion and possible speaker failure. Correct use of these filters can substantially increase the longevity and fidelity of your audio system.

Channel 1 & 2 Contro

Power

Bass Boost

High-Level Inputs

attenuate frequencies above the selected filter frequency at a rate of 12dB per octave. This is useful for connection of subwoofer(s) to one or both of the J2-320.4’s channel pairs in a bi-amplified system.

2)“Filter Freq. (Hz)” The J2-320.4 has separate Filter Frequency controls in each Channel Controls section for the low-pass filter and the high-pass filter. You will only use one of these in each channel section, depending on which “Filter Mode” you have selected (or none of them if you have selected the “Off” position for the “Filter Mode”).

The High-Pass filters in the J2-320.4 are fully

variable between 60 Hz and 1.2 kHz (1200 Hz) via

“BASS BOost” Controls

Each channel pair of the J2-320.4 includes a single band, boost-only bass equalizer controlled by a rotary knob marked “Bass Boost”.

This control has a boost range of 0dB (full- counterclockwise) to +12dB (full-clockwise) and

is centered at 45 Hz.

Bass Boost

Off +12dB

The preamp output signal is not affected by the “Bass Boost” processing selected for the amplifier or by any crossover filter selected (if the input signal is full-range, the preamp output will be full-range).

Note: The signal level of the “Preamp Output” is always line-level (low voltage).

Speaker OUTPUTS

The J2-320.4’s speaker outputs are designed to accept 16 AWG - 8 AWG wire.

Each pair of the J2-320.4’s channels are designed to deliver power into speaker loads equal to or greater than 2 ohms per channel when using

a “stereo” configuration and speaker loads equal

to or greater than 4 ohms per bridged pair of

Off +12dB
	40	150	60	1.2k
	40	150	60	1.2k
	Low-Pass		High-Pass
HP Off LP	Low-Pass		High-Pass
HP Off LP
Filter Mode	Filter Frequency (Hz)

the control knobs labeled “High-Pass”. The “8 o’clock” position corresponds to 80 Hz and is a

good starting point for system tuning.

The Low-Pass filters in the J2-320.4 are fully

HP Off LP

Filter Mode

Pre-OUTS

channels when using a “bridged” configuration.

Channel 1 & 2 Contr

Power

1) “Filter Mode” Control: The J2-320.4 employs a

12dB per octave filter for each pair of channels

(one filter for channels 1&2 and another filter

for channels 3&4). Each of these filters can

be configured independently into one of two

filter types or defeated completely by way of the

three-position “Filter Mode” switches:

“HP” (High-Pass):Configures the filter to

attenuate frequencies below the selected filter

frequency at a rate of 12dB per octave. This is

variable between 40 Hz and 150 Hz via the control knobs labeled “High-Pass”. The “12 o’clock” position corresponds to 80 Hz and is a good starting point for system tuning.

The J2-320.4 incorporates a pass-through preamp output section, so that additional amplifiers can be easily added to the system. This pass-through pre-amp output delivers a summed stereo signal , combining the Ch 1 and 3

signals into a Left Preamp Output Signal and the Ch. 2 and 4 signals into a Right Channel Preamp Output signal.

Bass Boost
		High-Level Inputs
Off +12dB
	40	150	60	1.2k
HP Off LP	Low-Pass		High-Pass
HP Off LP
Filter Mode	Filter Frequency (Hz)

useful for connection of component speakers

to one or both of the J2-320.4’s channel pairs in

a bi-amplified system.

Off”: Defeats the filter completely, allowing

the full range of frequencies present at the

inputs to feed the amplifier. This is useful

for systems utilizing outboard crossovers or

requiring full-range reproduction from one or

both of the J2-320.4’s channel pairs.

“LP” (Low-Pass):Configures the filter to

&4 rom

max

ens.

Pre-Outs

LEFT

RIGHT

CH 2

Speaker loads below 2 ohms nominal per channel are not recommended and may cause the amplifier to initiate a protection mode.

JL Audio